The golden hamster or Syrian hamster (Mesocricetus auratus) is a rodent belonging to the hamster subfamily, Cricetinae. Their natural geographical range is in an arid region of northern Syria and southern Turkey. Their numbers have been declining in the wild due to a loss of habitat from agriculture and deliberate elimination by humans. Thus, wild golden hamsters are now considered endangered by the International Union for Conservation of Nature. However, captive breeding programs are well established, and captive-bred golden hamsters are often kept as small house pets. They are also used as scientific research animals.

Syrian hamsters are larger than many of the dwarf hamsters kept as pocket pets (up to five times larger), though the wild European hamster exceeds Syrian hamsters in size.

Adult golden hamsters can reach around 7.1 in (18 cm) long. Females are usually larger than males, with a body mass of around 100–150 grams (3.5–5.3 oz) and lifespan of 1.5-2 years. Syrian hamsters from private breeders can be in the range of 175–225 grams (6.2–7.9 oz).

Like most members of the subfamily, the golden hamster has expandable cheek pouches, which extend from its cheeks to its shoulders. In the wild, hamsters are larder hoarders; they use their cheek pouches to transport food to their burrows. Their name in the local Arabic dialect where they were found roughly translates to "mister saddlebags" (Arabic: أبو جراب) due to the amount of storage space in their cheek pouches.

Sexually mature female hamsters come into heat (estrus) every four days. Golden hamsters and other species in the genus Mesocricetus have the shortest gestation period in any known placental mammal at around 16 days. Gestation has been known to last up to 21 days, but this is rare and almost always results in complications. They can produce large litters of 20 or more young, although the average litter size is between eight and 10 pups. If a mother hamster is inexperienced or feels threatened, she may abandon or eat her pups. A female hamster enters estrus almost immediately after giving birth, and can become pregnant despite already having a litter. This act puts stress on the mother's body and often results in very weak and undernourished young.^{[citation needed]}

Golden hamsters originate from Syria and were first described by scientists in the 1797 second edition of The Natural History of Aleppo, a book written and edited by two Scottish physicians living in Syria. The Syrian hamster was then recognized as a distinct species in 1839 by British zoologist George Robert Waterhouse, who named it Cricetus auratus or the "golden hamster". The skin of the holotype specimen is kept at the Natural History Museum in London.

In 1930, Israel Aharoni, a zoologist and professor at the Hebrew University of Jerusalem, captured a mother hamster and her litter of pups in Aleppo, Syria. The hamsters were bred in Jerusalem as laboratory animals.

Descendants of the captive hamsters were shipped to Britain in 1931, where they came under the care of the Wellcome Bureau of Scientific Research. These bred and two more pairs were given to the Zoological Society of London in 1932. The descendants of these were passed on to private breeders in 1937.